Thanks for all your help, guys.

I heard recently that RLV's Mac 101A pipe works well with this engine. They still sell the pipe, but the header remains a challenge.

Bingo on the pipe! Thanks VirgLove! Good price, too: $112. U.S. Motor Power part no. 300-820. Anyone have any experience with this pipe?

The header shown in the picture is not available. Any ideas on a header? I understand that RLV and Dave Bonbright are stumped on this, too.

I recently bought a couple of WB 820s. They are in good condition, ported, modern ignition, Tillotson HR 194 carbs (one per engine) set up for methanol. I currently have GEM cast aluminum can mufflers, which are limiting performance significantly. I want to go to expansion chamber exhausts, but have...